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Sisteme de Radionavigatie Aeriana

Octavian Thor Pleter, PhD, PhD, MBA (MBS)

This presentation draws on ideas from Dr. Pletersarticles, books, and unpublished manuscripts. No part of this

publication may be reproduced, stored in a retrieval system or transmitted by any means or in any form - electronic,

mechanical, photocopying, recording or otherwise - without written consent from Octavian Thor Pleter or the

Brainbond consultancy firm, www.brainbond.roVersion 2.0 dated 10 January 20014 O. T. Pleter and Brainbond

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RNAV = Area Navigation

The 1990 revolution of the classic airways network.

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A classic airway is marked by radio aids with coverage over the

entire routeNavigation is done by flying inbound the next aid

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Increasing the capacity over a classic airwaya new airway, with

its new set of radio aids

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RNAV Airways do not need radio aids to set up new routes, just

navigation fixes, and a full VOR-DME coverage for the area

navigation fix

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VOR-DME Navigation Aid Navigation Fix

hardware

cost:1-50 million

maintenance and

continuous monitoring

energy consumption

NILOV 44.953831 25.170303

software

cost:0just an entry in an

international database

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How could you replace a radio aid with a navigation fix?

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RNAV System

Air navigation system

Dedicated digital computer with software

Input from all available navigation sensors

Calculates current position

Calculates and displays the required information to fly direct to anynavigation fix (not only to radio aids):

Course Deviation (CD)

Distance To Go (DTG)

Relative Navigation Velocity (RNV) or Relative Ground Speed

Time To Go (TTG) or Estimated Time of Arrival (ETA)

Cross Track (XTK) and Track Angle Error (TKE)

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RNAV System

course

deviation(CD)

Distance to Go (DTG)

Relative Navigation Velocity

(RNV)

Estimated

Time ofArrival

(ETA)

to / from

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RNAV System Accuracy

Basic RNAVaccuracy to within 5 NM on 95% of time

Precision RNAVP-RNAVaccuracy to within 1 NMon 95% of time

RNAV System Dimensions

2D = route / horizontal / lateral guidance capability

3D = 2D + profile / vertical guidance capability

4D = 3D + timing / speed function

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sin 90AID

LPLAT LAT

R FL

cos 901

cos2

AIDAID

LP

LONG LONG LAT LAT R FL

RhoTheta Navigation

singular point: at thevertical of the radio aid

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RhoTheta NavigationGeometric Dilution of Precision (GDP)

we assume the POS ofthe aircraft at the

intersection of and

the aircraft could be

anywhere inside the

curved quadrangle atthe intersection of the

circular crown with the

width of 0.4 NM and the

triangle with the sharp

angle of 2.8

at worst, it could be in

one of the outer corners

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Problem: Aircraft Positioning by RhoTheta?

An aircraft in Bucharest FIR is en-route at FL400. NAV1 is tuned

to 113.20 MHz, RMI indicates QDR 291, DME indicates 59.5 NM,VAR is 4E. What is the position of the aircraft?

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ThetaTheta

Navigation

90 90 90LP QTE QDR VAR

0 2 1y LAT LAT R FL

1 20 2 1 cos2

LAT LATx LONG LONG R FL

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ThetaTheta Navigation

singularity: when the aircraft and

the two VORs are co-linear

1

0 2 0

tantan

y xy y x x

0 2 0

1 2

tantan tany xX

XY 1

tan

1

YLAT LAT

R FL

1

1

1

cos2

XLONG LONG

LAT LAT R FL

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ThetaTheta NavigationGeometric Dilution of Precision (GDP)

we assume the POS of theaircraft at the intersection of

1and 2

the aircraft could be

anywhere inside the

quadrangle at theintersection of the two

triangles with the sharp angle

of 2.8

the system is ill conditioned

near the singularity area(when 1and 2are near

equal or near supplementary)

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Problem: Aircraft Positioning by ThetaTheta

An aircraft in Bucharest FIR has NAV1 tuned to 113.20 MHz, and

NAV2 to 117.60 MHz. RMI indicates QDR1=291, and QDR2=253,VAR is 4E. What is the position of the aircraft?

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RhoRho Navigation

22

k k kDME FL ELEV

0 2 1y LAT LAT R FL

1 20 2 1 cos2

LAT LATx LONG LONG R FL

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RhoRho Navigation

no singularity; ambiguity between

the real solution and a false one

2

2

2

0

2

0

2

1

22

yYxX

YX

2 2 2 2

1 2 0 0z x y

22 2 2 2 2 2

0 0 0 0 1 0

, 2 2

0 0

4 4

2A B

z

zy z y x y xY

x y

AA YX 2

1

BB YX 2

1

+ or decided by replacing the

solution in the system above

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RhoRho NavigationGeometric Dilution of Precision (GDP)

we assume the POS of theaircraft at the intersection of

the circles1and2

the aircraft could be

anywhere inside the

intersection area of the twocircular crowns with the width

of 0.4 NM

the system is ill conditioned

when the two circles are

almost tangent, when the twosolutions are close to each

other

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Flight

Management

System(FMS)

=

Performance

Computer

+

4D RNAV

Navigation

Computer

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FlightManagement

System(FMS)

Block Diagram

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FMS gathers positioning

information from all availablesources, and uses Kalman

filtering to compute the best

estimate

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FMS

POS INIT Page

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FMS

RTE LEGS Page

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FMS

PROGRESS 1 Page

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